1. Field of the Invention
This invention relates to the field of telecommunication cable closures, and in particular to a sealing washer used with such closures and to a device for providing the required opening in such washers to accommodate telecommunication cables of various sizes.
2. Prior Art
In the telecommunications field, it becomes necessary to join telecommunications cables together at various points. Where this is accomplished by splicing the cables together, it is preferred to enclose the spliced connection within a sealed closure in order to protect the connection from moisture and other environmental factors. The telecommunications cable closures used in the field may be cylindrical in shape and provided with end plates having circular openings through which the telecommunications cables are introduced into the closure. Since the telecommunications cables introduced into the closures may be of various diameters, circular sealing washers whose purpose is partly to locate the cable in the center of the end plate as well as to seal the closure are disposed in circumferential grooves in the end plate openings. The end plates are fabricated in semicircular sections which close together around the sealing washer in clamshell like manner. The sealing washers therefore have an outside diameter equal to the diameter of the circumferential groove and an inside diameter equal to the diameter of the telecommunications cable being inserted through the end plates.
Two sealing washers are typically used, one on each side of the end plate. Between the sealing washers an uncured rubber sealing tape is wrapped around the telecommunications cable. The sealing washers prevent this uncured rubber tape from oozing out of the cavity in the end plate between the two sealing washers after the end plate is assembled. This arrangement of uncured rubber sealing tape, sealing washers, telecommunications cable and end plate have been found to provide a satisfactory closure for protecting spliced connections from moisture and other environmental factors where the telecommunications cable is introduced into the closure.
As the spliced connections and telecommunications closures referred to are often located in the field, they may be located in underground conduits accessible only through manhole covers, or near the tops of utility poles. If, during the course of installation or repair of spliced connections, a telecommunications repair person has not brought with him or her a particular sealing washer having an opening suitably sized to accommodate the particular telecommunications cable used, such person will be inconvenienced at having to return to his or her truck or work station in order to retrieve an appropriately sized sealing washer. Even greater inconvenience and loss of time results if in fact the repair person does not have an appropriate sealing washer in his or her truck or at his or her work station and must return to a supply depot in order to obtain the appropriate sealing washer. It will be appreciated, therefore, that it is advantageous to be able to fabricate a sealing washer having the appropriate opening in it in the field from a sealing washer blank.
Previously known sealing washers comprised an essentially solid disk of uniform thickness, often having a radial slot which might or might not extend all the way through the thickness of the sealing washer. The radial slot enables the sealing washer fabricated from the blank to be separated at the slot so that it can be twisted and inserted over a cable rather than slipped on over the end of the cable.
Prior to the present invention, the only known devices which have been used in the field in order to obtain sealing washers having appropriately sized openings have suffered from one or more shortcomings. One device, Western Electric No. 849A Sealing Washer Cutter, has a hinged mechanism for clamping one size of sealing washer blank on a table and a rotatable central shaft having a plate attached thereto to which movable blades for cutting the washer are attached. This device, of metal construction, is bulky and heavy and not suitable for carrying to all in-field locations. In particular, it is not believed that it was designed to be used or could safely be used by a repair person on a utility pole.
Another known device for providing appropriately sized sealing washers in the field is of West German origin and has been sold under the name "Krone". This device also includes a hinged mechanism and platform for clamping a sealing washer blank of a specified size and a rotatable shaft which is attached to a bladecarrying arm. This device is light in weight, but somewhat bulky. In addition, its blade is not easily adjustable.
Another device for cutting sealing washers is the WCT 10 of PSI Telco. This device is versatile in that it can fabricate sealing washers having specified outside as well as inside diameters. The device is comprised of a table having steps, an adjustable clamping mechanism for holding the sealing washers, and an adjustable rotatable blade. While light in weight, it is, nonetheless, bulky.
The cutting device of the present invention provides features which are not provided in any of the above discussed devices. With the portable adjustable washer cutter of the present invention, a repair person in the field, even atop a utility pole, may easily and quickly fabricate a sealing washer having a required inside diameter from a sealing washer blank. The cutter is both lightweight and compact, and can be disposed in an essentially flat pack or pocket, unlike the heretofore known cutting devices. This is accomplished in part through the use of an improved sealing washer blank having a ribbed construction and a pair of mounting holes for use in positioning the sealing washer blank on the cutter. By the use of the mounting holes in the sealing washer blank and corresponding mating pins on the cutter, the cutter dispenses with the use of a support platform around the circumference of the sealing washer blank as well as any clamping features which have characterized the heretofore known cutting devices. The ribbed construction permits the sealing washers blanks to be thinner where they are cut by the cutter than the sealing washer blanks previously used.